Gartner Research published "Server Operating Systems—UNIX vs. NT: Perspective" in January 2000. In this comprehensive report, some conclusions were reached about UNIX and MS Windows NT:

• UNIX has become the standard for building large-scale application servers (Internet services, database management), while NT is used primarily as a departmental server (messaging, file/print).
   
• Though its implementation may prove expensive, UNIX offers a higher degree of reliability and scalability than NT. This is measured by time span between reboots and percentage of uptime.
   
• Unlike UNIX, NT's file directory structure allows an application config file to be placed almost anywhere, which leads to problems, including having several versions of a single DLL file on the same system with the same filename.
   
• UNIX does not require administrators to reboot after making minor configuration modifications. NT does.
   
• With UNIX, there is a built-in ability to manage the machine remotely.

Industry experts on the move to UNIX

Many industry experts believe that the best way to gauge the success of database architectures is to do a market survey and choose architectures similar to those chosen by successful shops. For example, as of 2001, more than 95 percent of all Oracle data was stored in a UNIX environment.

"The NT market will grow faster than the UNIX market, but there are still more dollars in the UNIX market, where database management systems frequently sit on large servers and work for more users," said Merv Adrian, database analyst for the Giga Information Group Inc.

Susan Frankle, director of server research at IDC, said, "NT has made a significant impact on file server, print server and basic Internet applications, but it won't be all things to all people. Microsoft is very good at providing productivity applications support, but it does not really know how to support enterprise-wide networks and the applications that run on them."

Frankle adds, "The Windows software isn't widely accepted away from the Intel Corp. platform, and Microsoft lacks value-added service and support for installations on an enterprise scale."

Here are some other points by which to compare UNIX and NT.

64-bit processor speed

UNIX: UNIX supports a 64-bit architecture to allow for very fast processing speeds for mission-critical systems.

NT: Intel-based 64-bit processors are still considered too unreliable for production systems.

Ancillary tools

UNIX: All systems require additional vendor tools for backup, recovery, tape, and system management. The vast majority of these tools are provided solely for UNIX environments.

NT: Many hardware-level file management tools are not available for NT, and failure to get into a UNIX environment will severely limit the choices of systems management tools.

Maturity

UNIX: The UNIX operating system has been around for more than 20 years. During this time, UNIX has evolved into a sophisticated environment that supports a huge variety of systems with high reliability, excellent security, and proven hardware-level backup and recovery tools.

NT: Windows NT is less than 10 years old and has been struggling with serious reliability, security, and scalability issues.

Reliability
UNIX: UNIX servers have become extremely reliable as evidenced by their widespread use in banking applications. My clients with NT servers must reboot the servers each week to clean up RAM memory leaks.

NT: NT's unreliability is demonstrated in the system management tools. For example, NT Wolfpack cluster technologies' sole purpose is to provide failover when an NT server crashes and to attempt to provide high availability. When a UNIX CPU fails, the OS often continues processing without service interruption, and the server telephones its vendor to report the problem.

Scalability

UNIX: Sun and HP offer robust UNIX servers that utilize sophisticated SMP subsystems to achieve high performance and scalability. Large corporations that use Oracle choose a UNIX vendor who offers servers that can easily accept new RAM and CPU as demand increases.

NT: NT 3.1 through 4.0 Server supports up to four processors. NT 4.0 Server Enterprise Edition supports up to eight processors.

Security

UNIX: Although attacks on UNIX and Linux have become more frequent, the system has a solid history and was designed and built around a secure environment. With TCP wrappers, firewall capability, and the SOCKS library, the UNIX platform can be hardened into a reliable source of security.

NT: Windows NT servers are prone to attacks from external hackers and viruses. In October of 2001, those Oracle users unfortunate enough to use Oracle on NT experienced a catastrophic loss of data with the NIMDA virus. Gartner has predicted that by the end of 2006, 25 percent of large enterprises will carry hacker insurance. Gartner believes that if Microsoft's security flaws are not addressed, 75 percent of providers of computer security insurance will apply surcharges to premiums for NT users by the end of 2002.

Other migration considerations

Once the decision has been made, a migration to UNIX will involve the following tasks. Each of these tasks is a major IT decision and is normally made by a high-level IT manager.
 

• Choosing a UNIX hardware vendor (Sun, HP): Once chosen, the company must choose a SMP server according to projected short-term processing demands and choose a data server with fast scalability.
   
• Choosing the Network environment: The appropriate choice of routers and network hardware must me made to ensure adequate response time and eliminate network latency.
   
• Choosing a disk storage vendor: This step involves choosing a disk vendor and an appropriate RAID architecture for the data. To eliminate multivendor issues, management may want to go with the same vendor as the server (Sun, HP).
   
• Choosing a backup and recovery strategy: It is highly recommended that companies choose hardware-level Oracle backup and recovery, using one of the major vendor products such as Veritas or EMC. Companies will also need to choose a tape management system, choosing between ADSM, Legato, or Veritas.
   
• Planning the migration: A downtime window must be scheduled to allow the existing system to migrate into the new architecture. A UNIX expert will be contracted to install the Oracle server and ensure that the IT staff (and the new UNIX systems administrator) understand the installation.
   
• UNIX Training: All DBA and developers should attend a five-day course in UNIX. This training should be done immediately prior to the migration to minimize loss of knowledge.